Abstract
Garbage Collection (GC) has been a critical optimization target for improving the performance of flash-based Solid State Drives (SSDs); the long-lasting GC process occupies the flash resources, thereby blocking normal I/O requests and increasing response times. This is a well-documented problem, and a wide range of prior works successfully hide the negative impact of GC on the I/O response times. In this paper, however, we unveil another serious side-effect of GC, called the plane under-utilization problem. More specifically, while a plane is busy doing GC, the other plane(s) in the same die remain idle, as all the planes in a die share a single command and address path that is dedicated to the GC. We also note that most of the state-of-the-art proposals attacking the GC impact on I/O response times are not able to resolve the plane under-utilization problem, and in turn, miss a great potential to further improve the SSD performance. Thus, we next propose a scheduling technique, I/O-parallelized GC, which leverages the idle planes during GC to serve the blocked I/O requests. As a result, flash resources (planes) can be active during the most of GC time and the blocked I/O requests can get serviced quickly, and in turn, an improved SSD performance can be achieved. Using simulation-based evaluations over a wide variety of workloads, we show that the proposed I/O-parallelized GC scheme can improve the response times of the GC-affected I/O requests by 83% (reads) and 70% (writes), by increasing the average plane utilization from the (two planes-per-die) baseline 50% to 74.4% during GC. The I/O-parallelized GC is orthogonal to prior proposals that hide GC overheads; so, they can be combined for further SSD performance improvement.
| Original language | English |
|---|---|
| Title of host publication | HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing |
| Publisher | Association for Computing Machinery, Inc |
| Pages | 243-254 |
| Number of pages | 12 |
| ISBN (Electronic) | 9781450357852 |
| DOIs | |
| Publication status | Published - 2018 Jun 11 |
| Event | 27th ACM International Symposium on High-Performance Parallel and Distributed Computing, HPDC 2018 - Tempe, United States Duration: 2018 Jun 11 → 2018 Jun 15 |
Publication series
| Name | HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing |
|---|
Other
| Other | 27th ACM International Symposium on High-Performance Parallel and Distributed Computing, HPDC 2018 |
|---|---|
| Country | United States |
| City | Tempe |
| Period | 18/6/11 → 18/6/15 |
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All Science Journal Classification (ASJC) codes
- Computational Theory and Mathematics
- Computer Science Applications
- Software
Cite this
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Parallelizing garbage collection with I/O to improve flash resource utilization. / Choi, Wonil; Jung, Myoungsoo; Kandemir, Mahmut; Das, Chita.
HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing. Association for Computing Machinery, Inc, 2018. p. 243-254 (HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing).Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
TY - GEN
T1 - Parallelizing garbage collection with I/O to improve flash resource utilization
AU - Choi, Wonil
AU - Jung, Myoungsoo
AU - Kandemir, Mahmut
AU - Das, Chita
PY - 2018/6/11
Y1 - 2018/6/11
N2 - Garbage Collection (GC) has been a critical optimization target for improving the performance of flash-based Solid State Drives (SSDs); the long-lasting GC process occupies the flash resources, thereby blocking normal I/O requests and increasing response times. This is a well-documented problem, and a wide range of prior works successfully hide the negative impact of GC on the I/O response times. In this paper, however, we unveil another serious side-effect of GC, called the plane under-utilization problem. More specifically, while a plane is busy doing GC, the other plane(s) in the same die remain idle, as all the planes in a die share a single command and address path that is dedicated to the GC. We also note that most of the state-of-the-art proposals attacking the GC impact on I/O response times are not able to resolve the plane under-utilization problem, and in turn, miss a great potential to further improve the SSD performance. Thus, we next propose a scheduling technique, I/O-parallelized GC, which leverages the idle planes during GC to serve the blocked I/O requests. As a result, flash resources (planes) can be active during the most of GC time and the blocked I/O requests can get serviced quickly, and in turn, an improved SSD performance can be achieved. Using simulation-based evaluations over a wide variety of workloads, we show that the proposed I/O-parallelized GC scheme can improve the response times of the GC-affected I/O requests by 83% (reads) and 70% (writes), by increasing the average plane utilization from the (two planes-per-die) baseline 50% to 74.4% during GC. The I/O-parallelized GC is orthogonal to prior proposals that hide GC overheads; so, they can be combined for further SSD performance improvement.
AB - Garbage Collection (GC) has been a critical optimization target for improving the performance of flash-based Solid State Drives (SSDs); the long-lasting GC process occupies the flash resources, thereby blocking normal I/O requests and increasing response times. This is a well-documented problem, and a wide range of prior works successfully hide the negative impact of GC on the I/O response times. In this paper, however, we unveil another serious side-effect of GC, called the plane under-utilization problem. More specifically, while a plane is busy doing GC, the other plane(s) in the same die remain idle, as all the planes in a die share a single command and address path that is dedicated to the GC. We also note that most of the state-of-the-art proposals attacking the GC impact on I/O response times are not able to resolve the plane under-utilization problem, and in turn, miss a great potential to further improve the SSD performance. Thus, we next propose a scheduling technique, I/O-parallelized GC, which leverages the idle planes during GC to serve the blocked I/O requests. As a result, flash resources (planes) can be active during the most of GC time and the blocked I/O requests can get serviced quickly, and in turn, an improved SSD performance can be achieved. Using simulation-based evaluations over a wide variety of workloads, we show that the proposed I/O-parallelized GC scheme can improve the response times of the GC-affected I/O requests by 83% (reads) and 70% (writes), by increasing the average plane utilization from the (two planes-per-die) baseline 50% to 74.4% during GC. The I/O-parallelized GC is orthogonal to prior proposals that hide GC overheads; so, they can be combined for further SSD performance improvement.
UR - http://www.scopus.com/inward/record.url?scp=85050085372&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050085372&partnerID=8YFLogxK
U2 - 10.1145/3208040.3208048
DO - 10.1145/3208040.3208048
M3 - Conference contribution
AN - SCOPUS:85050085372
T3 - HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing
SP - 243
EP - 254
BT - HPDC 2018 - Proceedings of the 2018 International Symposium on High-Performance Parallel and Distributed Computing
PB - Association for Computing Machinery, Inc
ER -